Tremors caused by spinal malfunction

TThe mechanism which causes severe tremors in people with Parkinson's disease could be controlled through the spine, research on monkeys suggests.

Scientist know that mild tremors can affect healthy individuals on a daily basis, for example when we are hungry. Yet for the sufferers of the severe form, arising from conditions such as Parkinson's and Multiple Sclerosis, there is a great difference. Some patients are unable to walk unaided or complete routine daily tasks. A team of scientists wanted to find the mechanism responsible for this difference in tremor experience, with the hope of reducing the severity of tremors in these patients.

The researchers first studied body circuitry in healthy individuals. They calculated that constant brain waves from the area of the brain which controls movement means that everyone experiences mild tremors but in healthy people they are almost unnoticeable. The team then reasoned that there must be a mechanism that cancels out the tremors in healthy people but malfunctions in those who suffer from severe tremors.

To locate this mechanism, the team taught macaque monkeys to move their index fingers back and forth, to intensify the tremors usually felt in healthy monkeys and humans. Using sensors, the researchers recorded the activity of the brain and spinal cord nerve cells through which the brain signals travel. Both types of nerve cells showed activity but the spinal cord acted differently to the brain, cancelling out the brains ‘movement signals' and therefore reducing the tremors.

From this, scientists hypothesise that severe tremors may be linked to spinal malfunctions. Whereas previous research has focused on the brain, this study offers an alternate path to treat tremors through the spine.